Example embodiments relate to nonvolatile semiconductor memory devices, and more particularly, example embodiments relate to page buffers and nonvolatile semiconductor memory device including page buffers.
Nonvolatile semiconductor memory devices, such as flash memory device, are characterized by maintaining stored data in the absence of supplied power.
In the case of flash memory, the memory cells thereof are constituted by cell transistors each having a control gate, a floating gate, a source, and a drain. Each cell transistor is programmed or erased by selectively inducing Fowler-Nordheim (F-N) tunneling to set a threshold voltage of the cell transistor. In single-level cell (SLC) flash memory, each cell transistor is programmed (or erased) to one of two threshold voltages, thus defining 1 bit of stored data.
A relatively recent trend in flash memory technology is the development of multi-level cell (MLC) flash memory devices in which each cell transistor is utilized to store 2 or more bits of data. In MLC flash memory, each cell transistor is programmed (or erased) to more than two threshold voltages to thereby define 2 or more bits of stored data.